Real age of Michael Jackson in Back to the Future Part III
In the movie Back to the Future Part III, Michael Jackson was:
31 years old
That was the real age of the celebrity according to our calculation.
The calculation of the shown age took into account the first day of the year in which the movie Back to the Future Part III was released:
January 1, 1990
And the day in which Michael Jackson was born:August 29, 1958
Since movies usually don't take more than one year to be released since the beginning of the filming process, Michael Jackson may have been one year younger or one year older than the shown age while some scenes of the movie were being filmed.